<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<canvas id="screenCanvas" width="800" height="600"></canvas>
<script>
    let a = 100;
    let obj ={
        a:3,
        b:4,
        getA:function (){
            setTimeout(function (){
                console.log(this.a)
            },0)
        },
        getB:function (){
            let b = 10;
            console.log(this.b)
            return function (){
            }
        }
    }
    obj.getA();
    obj.getB();
</script>

</body>

</html>